This invention relates to window actuators for use in opening and closing single hung, double hung and horizontal sliding windows, with either a mechanical crank or power actuators which complies with: the requirements set forth in ANSI A117.1 as referenced by the Americans With Disabilities Act; and Chapter 12, 1204 of the 1991 Uniform Building Code ("Access and Exit Facilities and Emergency Escapes"). The invention can be used in both after market window conversions or can be incorporated into the design and manufacture of new window units.